ANN ARBOR, Mich. (AP) — Robot food delivery is no longer the stuff of science fiction.

Hundreds of little robots — knee-high and able to hold around four large pizzas — are now navigating college campuses and even some city sidewalks in the U.S., the U.K. and elsewhere.

While robots were being tested in limited numbers before the coronavirus hit, companies say pandemic-related labor shortages and a growing preference for contactless delivery have vastly accelerated their deployment.

Grubhub recently teamed up with Russian robot maker Yandex to operate 50 delivery robots on the campus of Ohio State University.

Grubhub says more campuses could be added soon.